instruction prefetch definition architecture
A technique which attempts to minimise the time a processor
spends waiting for instructions
to be fetched from memory. Instructions following the one currently being executed are loaded into a prefetch queue when the processor's external bus is otherwise idle. If the processor executes a branch
instruction or receives an interrupt
then the queue must be flushed and reloaded from the new address.
Instruction prefetch is often combined with pipelining
in an attempt to keep the pipeline busy.
By 1995 most processors used prefetching, e.g. Motorola 680x0
, Intel 80x86
[First processors using prefetch?]